The present invention relates to the art of earth boring and, more particularly, to an insert cutter having skewed inserts for contacting the formations being bored. The present invention may be advantageously used on tunneling machines, continuous mining machines, raise drills, rock bits, and other types of earth boring bits, cutters and machines. A cutter constructed in accordance with the present invention is rotatably connected to the bit or the rotary head of the earth boring machine and serves to contact and cut the formations being bored.
Insert type earth boring cutters include hard insert elements mounted in sockets in the cutter member body. The earth boring cutters are utilized in the boring of holes in the earth. The hard insert elements have the ability to penetrate earth formations; however, the cyclic loading due to cutter rotation during drilling imposes high unit loading on the insert elements, the sockets and the cutter member body. Such high unit loading can lead to failure of the cutter. In prior art cutters the axes of the inserts have been radially aligned with the axis of rotation of the cutter. The present invention provides an insert cutter having insert elements whose axes are skewed to the axis of rotation of the cutter.